Base-4 Keith numbers.

Terms

a(0) =5a(1) =7a(2) =10a(3) =15a(4) =18a(5) =29a(6) =47a(7) =113a(8) =163a(9) =269a(10) =1150a(11) =1293a(12) =1881a(13) =22173a(14) =44563a(15) =95683a(16) =261955a(17) =1179415a(18) =1295936a(19) =11451171a(20) =26867679a(21) =42531919a(22) =247791599a(23) =429914163a(24) =445379527a(25) =560533869a(26) =619222313a(27) =2147478019a(28) =2971786617a(29) =3474640372